verb: to half-turn, performing a half-turn
noun: a half-turn
The act of turning around and looking in an irritated way (possibly with rolling your eyes) to the person in the seat behind you, as a result of his noise-making.

the half turn is used in many situations. For one, its when your ina movie theatre or somewhere very quiet and someone behind you is making noise, you kind of halfway turn your head towards the, just so they know you hear them. another case is when you cut someone off driving and they honk angrily at you and you just kind of turn your head with a little smile to say "ya bitch" wothout actually saying it. even more offensive than the bird